The importance of electrical inspections in reducing fire risks

A guide to loss prevention

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Each year, there are more than 15,000 commercial building fires across England, Scotland and Wales, injuring more than 1,000 people*.

With electrical distribution being the main source of ignition in commercial fires*, there is an ever-increasing risk of property damage and personal injury.

The UK’s electrical infrastructure is aging. Commercial building electrical loads have increased, in some cases beyond the capacity of building transformers and electrical distribution systems.

In addition, business downsizings and restructurings can also result in the reduction or elimination of maintenance personnel, with key maintenance tasks falling by the wayside.

With only three common elements needed for a fire to initiate - oxygen, fuel and heat - electricity can play a pivotal role in the combustion process by providing the heat source; via short circuits, leakage current and overloaded circuits, to name a few. Third party inspections play an essential role in reducing fire risks to electrical systems.

Does the law require periodic inspection of electrical systems?

Employers and the self-employed are duty bound by the requirements of the Electricity at Work Regulations 1989 (EAW) made under the Health and Safety at Work Act 1974. The EAW Regulations require all systems and apparatus to be maintained and require proof that steps have been taken. Installations which conform with BS7671: Requirements for Electrical Installations are regarded by the Health & Safety Executive as likely to achieve conformity with the EAW Regulations, and this includes periodic inspection. Landlords have further legal obligations under the Consumer Protection Act 1987 (CPA). As a ‘supplier of goods’, the landlord must ensure that goods are checked before the tenant takes them over.

How often should the installation be inspected?

The frequency of period inspection is dependent on the type and use of the installation, the quality and frequency of maintenance and any external influences which the installation may be subject to. BS7671 provides guidance that the maximum period between inspection and testing is three to five years for most installations, but this could be more or less frequent depending on the installation.

A 'Competent Person', as specified under BS7671, should recommend the frequency on conclusion of their first inspection.

What is a 'Competent Person'?

UK

The UK Health & Safety Executive defines a 'Competent Person' as "someone who has the necessary skills, experience and knowledge to manage health and safety".

Depending on the particular legislation, the Competent Person can be either an individual or the body which employs the individual to provide inspection services.

Ireland

The 2005 Safety, Health and Welfare at Work Act defines a 'Competent Person' "where, having regard to the task he or she is required to perform and taking account of the size or hazards (or both of them) of the undertaking or establishment in which he or she undertakes work, the person possesses sufficient training, experience and knowledge appropriate to the nature of the work to be undertaken".

How can I be assured my electrical inspection provider is competent?

The services of the Competent Person should be formally accredited by UKAS to the international standards for inspection bodies (ISO/IEC 17020).

What should a periodic inspection include?

The installation is defined as the electrical system between the incoming supply point(s) and the final circuits. It may not include fixed appliances and associated supply cables or portable appliances, although these services may also be available.

A visual inspection of the complete installation should be carried out to verify if there has been any damage caused to the installation, and that the system equipment and cables have been correctly selected and adequately erected.

The inspection should also include the following testing:

Functional testing and security of switchgear operations.
Protective conductor continuity tests to measure the earth continuity between the earth terminal of switchgear and distribution boards to accessible exposed conductive parts of the installation (such as conduit).
Bonding conductor and supplementary bonding conductor continuity tests to verify the quality of earth continuity to metallic parts which are not part of the electrical system (such as water pipes).
Insulation resistance tests to measure any deterioration of the cable insulation between live conductors and earth.

Polarity of live conductors tested at the origin, distribution boards and at final circuits, including socket outlets and 10% sampling of light switches. Equipment connected to (or plugged into) a reversed polarity supply can become damaged, particularly electronic equipment.
Earth fault loop impedance testing at the origin, distribution boards and final circuits, including socket outlets, to verify the resistance of the line conductor to the earth conductor. This ensures that the current created under fault conditions will safely operate the protective device.
Prospective short-circuit current measurement at the origin and distribution boards to verify that the highest current which can exist in the system under sampling of light switches. conditions is not excessive.

RCD testing to confirm that RCDs trip within the recommended times and do not provide nuisance tripping. A functional test should also be conducted.
Phase rotation tests at the origin and distribution boards to verify the consistency of rotation throughout the installation.
Earth electrode resistance measured where applicable.
Ring circuit continuity may not be included where previous test records are available.

What should be included in the report?

The EAW Regulations and the CPA make reference to retaining documentary proof. Within agreed limitations, the inspection report should include observations and recommendations, schedules of test results on all circuits and give an assessment of the condition of the installation. It should also include a list of the instruments used and their respective calibration date. The Competent Person conducting the inspection will appoint one of three Classification Codes to each observation recorded during the inspection.

* Fire Statistics: April 2013 to March 2014 - Department for Communities and Local Government and Fire and Rescue Statistics, Scotland, 2013-14 - The Scottish Government

HSB Inspection Services

Our electrical wiring inspection services can help customers to achieve regulatory compliance and mitigate electrical wiring risks via our technically expert network of Engineer Surveyors; who are ‘Competent Persons’ under BS7671. As well as assisting property owners, commercial landlords and facilities managers, our inspection services extend to include quarry wiring inspections, public area licences, HV wiring (visual inspection only), and petroleum wiring inspections.

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